US4199396AExpiredUtility

Method for producing single crystal gadolinium gallium garnet

52
Assignee: UNION CARBIDE CORPPriority: Jun 24, 1976Filed: Apr 26, 1978Granted: Apr 22, 1980
Est. expiryJun 24, 1996(expired)· nominal 20-yr term from priority
Inventors:Charles D. Brandle, Jr.John B. Hassell, Jr.
C30B 15/00C30B 29/28
52
PatentIndex Score
11
Cited by
18
References
6
Claims

Abstract

Method for producing virtually perfect massive unicrystalline gadolinium gallium garnet from a melt of gadolinium and gallium oxides containing an addition of calcium, magnesium or strontium ions.

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
       1. Method for producing a virtually perfect unicrystalline gadolinium gallium garnet boule having a diameter of about 2.2 to 3.2 inches which comprises: (i) forming a melt by heating a mixture of Gd 2  O 3  and Ga 2  O 3  in molar ratio of 3:5 initially containing less than about 10 ppm in the aggregate of calcium, magnesium and strontium, and adding a predetermined amount of at least one metal ion selected from the group consisting of calcium, magnesium and strontium to provide from about 15 to 100 ppm in the aggregate of selected metal ion in the melt, the melt being at a temperature in the range of 1700° to 1800° C.   (ii) inserting a seed rod of unicrystalline gadolinium gallium garnet into the melt,   (iii) maintaining an atmosphere over the melt which is substantially chemically inert to the melt, and   (iv) withdrawing the seed rod from the melt such that gadolinium gallium garnet material is solidified and crystallized on the seed rod to form a virtually perfect massive unicrystalline product of increasing length and substantially circular cross-section having a growth axis common with the longitudinal axis of the seed rod.   
     
     
       2. Method in accordance with claim 1 wherein about from 15 to 25 ppm in the aggregate of selected metal ion is provided in the melt. 
     
     
       3. Method in accordance with claim 1 wherein from about 25 to 100 ppm in the aggregate of selected metal ion is provided in the melt. 
     
     
       4. Method in accordance with claim 1 wherein the selected metal ion is calcium and about 25 ppm of calcium ion is provided in the melt. 
     
     
       5. Method in accordance with claim 1 wherein the selected metal ion is calcium. 
     
     
       6. Method in accordance with claim 1 wherein the selected metal ion is calcium and about 50 ppm of calcium ion is provided in the melt.

Cited by (0)

No later patents cite this yet.

References (0)

No backward citations on record.